Background on Stars

Link to Spanish version of Earth Science Reference tables,
The Hertzsprung-Russell star chart is on page 15.
:

http://www.nysedregents.org/esrt/2011/esrt-11sp.pdf

English version:
http://www.p12.nysed.gov/apda/reftable/earthscience-rt/esrt2011-engr.pdf

File:HRDiagram.png

Here is the color chart, retrieved 3\2\12 from
http://en.wikipedia.org/wiki/File:HRDiagram.png
Powell, R, access granted.18 May, 2011.

Here is a fantastic interactive diagram:
http://lcogt.net/files/flash/hr-diagram/main.html